Drills using rotatable bits for penetrating into the earth are in widespread use. One application of such drills is in connection with a machine known in the vernacular as a “roof” bolter (even though it is capable of use with faces besides the roof of a mine passage, such as the ribs.) Typically, such a roof bolter is capable of both forming (drilling) boreholes in the faces of the passageways of underground mines and then installing roof anchors or “bolts” in the boreholes. As is well-known in the art, the bolts once installed provide support for the adjacent portion of the mine face, thereby reducing the incidence of catastrophic cave-ins.
In the conventional bolting operation, once the borehole is created using the drill, the bolt in anchored in place. One way of doing so is to introduce resin or grout into the borehole, typically in cartridge form. The drill head is then used to insert a roof bolt into the borehole to rupture the resin cartridge. Once ruptured, the bolt is rotated using the drill head to mix the resin, which is designed to quickly set and form a secure bond with the material surrounding the borehole. Another manner of bolt anchorage is to use an expansion shell, various forms of which are known in the art.
One area of continuing development with relation to the roof bolting method is the step of automating the drilling of the bore hole and the insertion of the bolt into it. Originally, the operator of the roof bolting equipment worked from the mine floor operating the drill for forming the bore hole and inserting a resin cartridge and bolt by hand. Although the manual operation works-well in narrow seams, it is obviously a tedious and time consuming process. Thus, significant attention has been developed to automating the process during the past fifty years. However, current automated drilling and bolting machines are not well-suited for use in the confines of a low seam environment, where the height of the mine passage is less than about six feet.
Accordingly, a need is identified for an improved drilling and bolting module and, in particular, one especially adapted for use in low seam/narrow passage environments.